1. Field of the Invention
This invention relates to handheld devices and, more specifically, to a helper environment for extending the capabilities of handheld devices by using nearby devices.
2. Background and Related Art
Digital handheld devices, for example but not by way of limitation, Personal Digital Assistants (PDAs), cell phones, digital cameras and portable MP3 players, have become part of our daily lives. Although each type of handheld device has its own unique characteristics, they generally share common features such as being small in size, being utilized in mobile environments, and containing data processing engines. While these common features make handheld devices very useful and extremely popular, another commonality does not bode well for them: these devices are generally limited in capabilities, especially in terms of screen display, processing power, storage space and network access. Some of these limitations, such as the small screen sizes, are inherently difficult to improve given the usage model of these devices. Often, handheld devices are used near fixed devices that do not suffer from the aforementioned limitations. Accordingly, what is needed in the art is a framework for a handheld device to use the increased capabilities of nearby fixed devices without sacrificing its desirable characteristics such as its small size and mobility.
Some attempts have been made at promoting the interaction between a handheld device and nearby fixed devices. For example, AT&T™ Laboratories developed a teleporting system whereby application interfaces, rather than the computers on which the applications run, are able to move. The teleporting system is implemented using a proxy server. All of a user's applications connect to this proxy server instead of the regular server. This makes it possible for the proxy server to reroute the user input and output to different displays according to the user request. A further enhancement to the teleporting model is to use a digital badge together with sensors in different rooms to identify user locations. User displays can then be automatically rerouted to the display closest to the user.
Subsequently, a more generalized form of teleporting, the Virtual Network Computing (hereinafter “VNC”) platform has been developed. It supports cross-platform operation by extending the teleporting system to different windows environments. Both the teleporting model and the VNC platform focus on a remote display system that allows a user to view a computing “desktop” environment not only on the machine where it is running, but from a mobile device as well.
A shortcoming of both the teleporting model and the VNC platform is that they are designed to migrate user interfaces to display devices that have similar capabilities as the original device. Another shortcoming of both the teleporting model and the VNC platform is that they only perform display migration.
The Pebbles project of Carnegie Mellon University represents another attempt at promoting the interaction between a handheld device and nearby fixed devices. The Pebbles project explores the potential of using PDAs as adjuncts to the fixed computers in a networked environment. As part of the project, several applications have been developed. For example, the SlideShow Commander application enables a PDA to serve as a remote control device to manage a presentation from the PDA. Other applications such as remote clipboard and remote mouse can also be used by installing the necessary software packages on both the PDA and the computer.
While the Pebbles project embodies a helper concept, the role of helper is played by the PDAs. The PDAs are used as helpful peripheral devices for the fixed devices. In general, the PDAs in the Pebbles project are used for control purposes. A shortcoming of the Pebbles project is that the addition of a new application requires installing additional software on both the PDA and the fixed devices.